Conventionally, in a UTRAN (Universal Terrestrial Radio Access Network) scheme of Release 0.6, mobile stations UE are configured to transmit a “CELL UPDATE message” to a radio access network in a “CELL UPDATE procedure.”
In the conventional UTRAN scheme of Release.6, the maximum amount of data that a mobile station UE can transmit with a “CELL UPDATE message” in a radio access network is specified to be 20 bytes.
Here, in the conventional UTRAN scheme of Release.6, a function called “Additional Dynamic Transport Format Information for CCCH” is specified. In a radio access network supporting such a function, mobile stations UE supporting the function are configured to be capable of creating and transmitting a “CELL UPDATE message” including an information element with a data amount of 20 bytes or more.